Pasteurization of pumpkin juice by continuous system thermosonication

The aim of this study; is the pasteurization of pumpkin juice with the addition of citrus peel essential oil (CPEO) and the combined application of continuous system thermosonication (CST). For this purpose, firstly, the antimicrobial effect of CPEO was determined. CPEO added pumpkin juice samples were processed in the CST for 4 cycles at 40, 45 and 50 °C, and 3rd cycle at 50 °C condition provided the 5 log reduction in the number of target microorganism Escherichia coli K-12 . Samples produced under this condition and control samples (CPEO added, not treated) were produced and monitored for 16 days in terms of their microbial, physicochemical and bioactive properties. The total mesophilic aerobic bacteria content of the CST-treated samples did not exceed 102 cfu/mL during storage. The ∆E values of the CST-treated samples were lower for the first 12 days. pH values remained stable, but the total titration acidity, total water-soluble solids and turbidity of the samples increased during storage. While the samples were close in terms of total phenolic substance, CST-treated samples increased by 3.1 times in terms of total flavonoid substance. At the end of storage, the control and SST samples were respectively; decreased by 94.2 and 77.8% in terms of FRAP, and by 20.6 and 73.5% in terms of DPPH. In the sensory evaluation, CST-treated samples received higher scores than the untreated samples in terms of odor, aroma, flavor, sweetness and general taste criteria. In our study, information infrastructure has been provided for the production of pumpkin juice with innovative technologies.